Electric controller



PATENT oFFlcE.

RICHARD AMBERTON, OF LONDON, EI'CJrLAlI'D.l

ELECTRIC CONTROLLER Specification of Letters Patent. Patgiltgd Sept 20, 1921.

Application filed March 3, 1920. Serial No. 362,947..

To aZZ whom t may concern:

Be it known that I, RICHARD AMBERTON, a subject of the King of Great Britain, and residing at Vauxhall Works, South Lambeth Road, London, S. WV. 8, England, have invented certain new and useful Improvements in Electric Controllers, of which the following is a specification.

This invention relates to controllers. such as are used for varying the connections or for cutting in or out resistances in electric circuits. It is the object of the invention to reduce or eliminate sparking at the controller contacts by the use of a single contactor arranged in such a manner that it operates repeatedly and substantially performs each successive operation of cutting resistance in or out, or of varying thel electrical connections, as thecase may be.

' In the accompanying drawing' are shown diagrammatically two forms of electric `controllers accordingto the present invention.

Referring first to Figure l, the main contact arm or brush a, which worksr over a contact plate d, carries an auxiliary contact arm b mounted thereon byinsulated supports 0,' this auxiliary Contact, arm works over a contact plate e which is adapted to be connected to the plate Z of the main contact arm a and the load circuit f through a conl tactor switch g. The coil ofthe contactor switch g is in a circuit It which forms a shunt with the load circuitf, one end of the circuit -t being connected to the plate d, while the other end isconnected to contact studs y' which are adapted to be brought into electrical connection with controller studs -7c", 7a2, 7c3 bymeans ofthe auxiliary contact v ranged that on the movement of the'contact the studs j.

over which it has been moved. The arm ais provided with suitable insulator plates Wt, n so as to prevent any electrical connection between thefarm a and the platee or The apparatus is shown as controlling an electric motor, whose armature is marked. l and whose eld is marked 2. i

The operation of Vthe electric controller shown in Fig. l is as follows Assuming the main brush a to be on one contact 7c and that a step of resistance is to be cut out of circuit, the controller handle is moved forward in the direction of the arrow. n The `auxiliary contact arm b first reaches the next main controller stud lc', but .t

as the contactor switch g which is normally l open, is interposedbetween it and the load circuit f, no current iows.

Afurther forward movement will cause the arm b to bridge the gap between the first stud y' and the second controller stud 70?, thus closing the circuit Iz. and energizing the operating coil 0 of the contacter switch g.

The -contactor switch g is thus closed and a step of resistance Z is cut out of the load circuit f, thecurrent now flowing through the plate d, contactor switch g, `plate c, contact arm Z), controller stud c and resistances Z, Z2. The arm a, however, still makes connection between the plated and the stud 7o, but with the resistance Z in circuit.

' As the forward movement is continued the main `brush t leaves stud lc and reaches the stud 7c but the resistance Z havingbeen cut out as-previously described and the contact arm ,b being still fully in contact with the stud/t" no deleterious sparking occurs. A slightly Vfurther forward movement disestablishes the contact between the arm Z) and the intermediate stud y' and the contactor switch circuit Zz. is opened, leaving the circuit closed through arm a, and stud ZJ. ycontroller is now ready tobe moved forward to cut out the next step of resistance, when the cycle of operations will be the same as previously described. On moving backward to cut .in resistance, these operations are reversed, as it will be seen that on cutting in a step of resistance, the circuit through the auxiliary arm b will be broken at the contacter g when the arm Z) leaves a stud j, but the arm a will then be fully in contact with thestud of the controller which connects the further step of resistance in circuit.

The i In addition t0 the studs j, other studs may be provided which are adapted to be connected to operating coils of otherl contactor switches, their circuits being opened or closed by the passage either of the main contact arm or of the auxiliary contact arm b over these studs.

An example of such an arrangement is shown in Fig. 2, wherein a Second contacter p is controlled by the main contact arm a passing over studs g so as toV prevent risk of sparking on the main contact arm it the first contactor fails to operate correctly.

The general arrangement according to Fig. 2, corresponds to that described in connection with Fig. l. According to Fig. 2 a contactor p is provided, the operating coil of which is adapted to be energized for closing the contacter v when the arm a is in the starting position and by means of a projection s thereon. which closes a lswitch t oil a circuit u, 1u connected to the main load circuit f. In the circuit u is also arranged a switch e' which is normally closed but is adapted to be opened by an arm p bearing on the tail piece of switch o, when the contactor p is closed. The coil r is connected to the studs g through a resistance w and a conductor and to the contactor g by the resistance w, conductor g/ and contacts e.

The studs g are so arranged that Contact between them and the arm a is not broken as the controller arms are moved forward, until thearm b makes contact with the next stud j and vice versa. The gap between the studs 7c, 7c', k2 and 7c3 and between the studs y' Vand g is of course always such that it is impossible for either the arm a or the arm ZJ to bridge the gap between the respective studs. p

The operation of the controller shown in Fig. 2 is as follows Assuming that the controller is in the starting position and the main switch has been closed, the arm a., by means ofthe projection s, will close the switch t, and as the switch o is normally closed, a current will iiow :from one terminal of the load circuit f, through circuit u, switches t and c, coil r and conductor u', to the other terminal of the load circuit 7. The contactor 7) is thus closed and the switch c is opened by means of the arm p. As the main arm a is also on the iirst stud Qa current will -How from the load circuit f, conductor f', contactor p, plate d, arm a, stud g, conductor resistance w, coil r, conductor a to the other end of the load circuit f and thus keep the contact'or p closed. The main current will now also iiow from the arm a, through stud 7c and the resistances Z, Z, Z2, to the motor.

In order to cut out a step of resistance Z from the load circuit f, the controller will be moved in the direction of the arrow and the arm b, when it comes into contact with the rst stud j, will close the circuit Zt of the contactor g as in Fig. l. In addition to this operation, however, the circuit of the contactor y) must be kept closed and for this purpose the contactor g when operated, must also close contacts .e so as to form a. shunt circuit which passes from the contactor g, contacts e, conductor y, resistance w, coil r and conductor u to the other terminal of the load circuit f. rIhe contacter y) is thus kept closed during the operation oi' the controller, If, however, the contactor f/ fails to act, then the circuit or the operating coil r of the contactor p would be denergized and the main circuit broken at 7; without any deleterious sparking occurring when the arm a leaves the stud g. This occurs before the arm t leaves the stud 7c so that any deleterious sparking is avoided. The controller is now ready to be moved forward to cut out the next step of resistance, when the cycle of operations will be the same as previously described.

For the purpose of cutting in resistance,

the operations are reversed, as it will be seen that on cutting in a step of resistance, the circuit through the auxiliary arm will be broken at g when the arm Z) leaves a stud j, but the arm a will then be fully in contact with the stud of the controller which cuts in a further step of resistance in the load circuit, and this arm a will also be in contact with a stud g so that the coil r remains energized and consequently holdsthe contactor p in the closed position. y

Having thus described my invention what I claim as new and desire to secure by Letters Patent is s l. An electric controller comprising a plurality oit' contact plates, a plurality of contact studs, a plurality of resistance studs, resistances connected to said studs, a main contact arm, said contact arm being adapted to form electrical connection between one contact plate and the resistance studs, an auxiliary contact arm, said auxiliary contact arm forming electrical connection between a second contact plate, the resistance studs and the contact studs, a contacter adapted when 4operated to form electrical connection between the contact plates, and electrical means for operating said contactor, said electrical means being controlled by the auxiliary contact arm in such a manner that the contacter operates repeatedly and substantially performs each successive operation of cutting resistance in and out, and of varying the electrical connections.

2. In an electric controller comprising a plurality of Contact studs, a plurality of re` sistance studs and resistances connected to the resistance studs, the combination with the main contact and auxiliary contact making members operatively connected therewith of a contactor, electrical means ior operating the contactor and controlled by the main contact, said electrical means being so arranged that the contactor operates repeatedly and substantially performs each successive operation of cutting resistance in and out, and of varying the electrical connections.

3. In an electric controller the combination comprising a main contact arm, an auxiliary contact arm, a contactor, and electrical means for operating said contactor, electric circuits, said electric circuits being adapted to be controlled by said contactor, said electrical means being controlled in such a manner by the auxiliary .contact arm that the contactor makes and breaks successive circuits in advance and separately from the main contact arm.

4. In an electric controller the combination comprising a main contact arm, an auxiliary contact arm, a contactor, a plurality of resistances, electrical means for operating the contactor, said electrical means being controlled by the auxiliary contact arm in such a manner that when resistances are cut in and out the make and break in the circuit is effected by the contactor.

5. In an electric controller, the combination comprising a plurality of contact plates, a main contact arm and an auxiliary contact arm, the main contact arm being adapted to contact with one of the contact plates and the auxiliary contact arm with a second contact plate, a contactor adapted when operated to connect the two contact plates, and an electric operating circuit for said contactor, said operating circuit being controlled by the auxiliary contact arm. y

6. In an electric controller the combination comprising a plurality of contact plates, a main contact arm and an auxiliary contact arm, the main contact arm being adapted to contact with one of the contact plates and the auxiliary contact arm with a second contact plate, a contactor adapted when operated to connect the two contact plates, an electric circuit including an operating coil for the contactor and contact studs, said contact studs being so arranged in the path of the auxiliary contact arm that the said contact arm does not make contact with one of the contact studs until it is fully in contact with a resistance stud and while the main contact arm is still in contact with the preceding resistance stud, and that contact between the contact stud and the auxiliary' contact plate is only broken when the main contact arm is fully in contact with the next resistance stud and before the auxiliary contact arm commences to leave said contact stud.

7 In an electric controller the combination comprising a main contact arm, an auxiliary contact arm, a contactor, an electric operating circuit for said contactor, said circuit being controlled by the auxilary contact arm, a circuit breaker, and electrical operating means for said circuit breaker, said electrical means being controlled by the contactor.

8. An electric controller comprising in combination two contact plates, a main contact arm, as auxiliarycontact arm, the main contact arm being adapted to contact with one of the contact plates while the auxiliary contact arm contacts with the second con tact arm, an auxiliary contact arm, the main contact arm being adapted to contact with one of the contact plates while the auxiliary contact arm contacts with the second con` tact plate, a contactor between the two plates, an electric circuit including an operating coil for said contactor and contact studs arranged in the path of the auxiliary contact arm, resistances with studs in the path 01"; the main contact arm and of the auxiliary contact arm, a second series of studs arranged in the path of the main contact arm, a circuit breaker, an operating coil for said contact breaker, electrical -means connecting the operating coil to the second series of studs, and electrical means 'for controlling the circuit breaker by means of the contactor.

`10. An electric controller comprising in combination two contact plates, a main contact arm, an auxiliary 'contact arlm, the main contact arm being adapted tocontact with one of the contact plates while the auxiliary contact arm contacts with the second contact plate, a contactor between the two plates, an electric circuit including an operating coil for said contactor and contact studs arranged in the path of the auxiliary contact arm, resistances with studs in 'the path 01"' the main contact arm and of the auxiliary contact arm, a second series of studs arranged in the path of the main contact arm, said second series of studs being so arranged that the main contact arm does not leave any one ofthe second series of studs until the auxiliary contact arm is in contact with its corresponding stud of the first series of studs and s0 that the auxiliary contact arm` does not leave its stud of the irst series or" studs until the main contact arm is in contact with the next stud of the second series of studs in its path, a circuit breaker, an operating coil for said contact breaker, electrical means connectingthe operating coil to the second series, of studs, and electrical means for controlling the circuit breaker by means of the contacter.

11. In an electric controller the combination comprising` two contact plates, resistance studs and resistances connected there-to, a main contact arm, an auxiliary contact arm, the main contact arm being adapted to contact With one Contact plate and the auxiliary contact arm with the second contact plate, While both tbe main contact arm and the auxiliary contact arm are adapted to Contact with the resistance studs, a contacter between the Contact plates, an operating coil for the contacter, contact studs in the path of the auxiliary contact arin and connected to the operating coil, a circuit breaker, an operating coil for said circuit breaker, means for controlling the operatingY coil. of the circuit breaker by the contacter', contact studs in the path of the main contact arm and connected to the operating coil of the circuit breaker by electrical connections including a resistance, an electric circuit for the operating coil of the circuit breaker, said circuit including switches one oi' which is held closed when the inain Contact. arm is in the starting position but is opened as soon as the con troller handle is moved from this position when the operating' coil is energized by the inain Contact arm being in Contact with one of its studs, While a second switch in said circuit is'opened by the circuit breaker when the operating coil thereof is energized, and electrical connection between the contacter and the operating` coil of the circuit breaker, the arrangement'being-` such that the circuit breaker rein-aine closed during the operation oi3 the main Contact arin unless the contacter fails to act when the circuitfbreaker is opened.

RICHARD AMBERTON. 

